I'm a combination Drupal and WordPress developer and have recently started playing with Drupal's Panels module -- which allows you to create flexible layouts and drop content blocks (The Drupal equivalent of widgets) in place on either a per-layout or per-content item basis.
I'm now working on a WordPress project that would really benefit from this kind of functionality — is there anything in WordPress at the moment that even slightly resembles Panels? I guess PageLines is a bit like that, but that's pretty expensive. I also came across "Drag and Drop Visual Editor and Publisher", but I tried the demo and it's full of typos and looks really beta.
(FWIW, I know I'm complaining that a commercial project is too expensive and that an open-source project looks non-commercial -- but c'mon, WordPress has 6x the adoption rate of Drupal, it has to have this kind of fairly important functionality somehow.)